Being unable to do something, through lack of sufficient ability, power or means – it
may be a physical impairment or handicap in some other area, which makes us feel vulnerable and incompetent. Satan would endeavour to use this as a reason why we should disqualify ourselves from any effective service in the Kingdom of God. God told

Don’t excuse yourself from what you should attempt

Paul, “My grace is sufficient for you, for my power is made perfect in weakness”; literally meaning His power shows up best in weak people – those that recognise in themselves they can’t do it without His enabling. Paul declared, when I am weak I learn to rely more on Him so in effect then I am strong (2 Cor 12:9,10). It is good to attempt to address the areas of weakness or areas we are deficient in, not so we become self-reliant and think we don’t need the Lord’s help but rather so He can use us in a greater way in spite of them. We must always be mindful, that “I can do all things [that He requires of me] through Christ [not independent of Him] who gives me strength” (Phil 4:13).

On our own we are no match for Satan’s sneaky schemes, so we must be like Jesus and when tempted declare the Word of God (Mt 4:1-10). We can’t walk in the ways of righteousness without His help, for “It is not for man to direct his steps” (Jer 10:23).

See also: ability, comfort zone, handicap, incompetence, weakness.